In a wireless cellular network, a terminal usually has the following three states: detached state, idle state, and active state. In order to satisfy requirements of normal operation of terminals in different states, the network provides at least one of the following network functions: a synchronization function, a broadcast function, a paging function, a unicast function, and a multicast function. To achieve the above network functions, the network side needs to issue the following downlink signals correspondingly: a synchronization signal, a broadcast signal, a paging signal, a unicast data signal, a multicast data signal, a bottom layer control signal, a high layer dedicated control signal and a pilot signal. The corresponding relationships between the network functions and the downlink signals are as follows: the synchronization function corresponds to the synchronization signal; the broadcast function corresponds to the broadcast signal, the bottom layer control signal and the pilot signal; the paging function corresponds to the bottom layer control signal, the pilot signal and the paging signal; the unicast function corresponds to the bottom layer control signal, the pilot signal, the unicast data signal and the high layer dedicated control signal; the multicast function corresponds to the bottom layer control signal, the pilot signal and the multicast data signal.
In the prior art, for a terminal, these various signals are transmitted by a same base station. It results in reduction of the network energy efficiency, for example, the high cost of control signaling, the network configuration which is not flexible enough and the space which is lack of optimal design and etc are caused.